Cursus Philosophicus Thomisticus, Prima Pars Artis Logicae

THAT THIS DIVISION IS ANALOGICAL is thought by various authors, moved by different grounds. Some seem to derive this from St. Thomas, who appears to teach it expressly in opusc. 48, treatise On Enunciation, chapter 6,¹ and On Interpretation 1, lecture 8,² since a hypothetical proposition is not one simply, but one by conjunction, as the Philosopher says in the same place, in the chapter On Enunciation.³ But the account of being and of one being is the same; therefore what is not simply one proposition is not simply a proposition.

Others rely on another ground: they think that at least conjunctive and disjunctive propositions are not, strictly speaking, hypothetical propositions, because they do not signify an enunciative connection, but merely contain propositions joined together accidentally, that is, by the mere simultaneity of utterance.

I SAY, FIRST: The division of proposition into categorical and hypothetical is substantially a division of genus into species, although it has a certain mode of an analogical division.

This view is more common among Thomists and is drawn from St. Thomas, opusc. 48, treatise On Enunciation, chapter 6,⁴ where he first says that this division is as an analogate into its analogates (the word as here indicates a mode), but later adds that this division divides proposition with respect to substance, because it divides it on the side of copulation or conjunction; the division into affirmative and negative, however, divides with respect to quality; and finally the division into universal and particular divides with respect to quantity. St. Thomas therefore holds that the hypothetical pertains to the substance of proposition, and hence that proposition is preserved univocally in it, because its substance is preserved. Accordingly, he finally adds⁵ that when we ask what proposition is, we ask about the substance of proposition, and thus answer that it is “categorical and hypothetical.” Therefore whoever says “hypothetical proposition” says “the substance of proposition.” Nevertheless, because on the side of the thing signified categorical and hypothetical stand as one and many, one prior and the other posterior, it is said to have a mode of analogy, as we shall explain later.

THE FOUNDATION OF THE CONCLUSION consists in this: a hypothetical proposition has everything required for the essential character of an enunciation, insofar as it is hypothetical. For as such it is a complete discourse, and not under the species of an optative, interrogative, or any other kind; therefore it is enunciative.

The antecedent is clear. That it is discourse is evident, since it has significant parts and is not a mere expression, but a mode of knowing. That it is complete is clear because it leaves the hearer’s understanding not suspended, but complete, as when I say: “Peter runs and John sits”; “If Peter runs, Peter moves.”

The consequent, however, is evident: First, by considering the species of complete discourse that we set out above, at the beginning of this question, from St. Thomas. A hypothetical proposition does not make discourse optative, vocative, imperative, or interrogative, as is clear in these propositions: “If a human being runs, he moves”; “John reads and Paul debates.” Therefore it must be enunciative. Also, a hypothetical proposition, insofar as it is such, signifies a truth or falsity distinct from that of a categorical proposition. For judgment is made not only about each categorical proposition but also about the hypothetical conjunction itself—not with respect to the arrangement of inference as in a consequence, but with respect to whether it is or is not so. This is clear in the proposition: “If a human being were a horse, he would be hinnible.” A false judgment is formed about each of the categorical propositions, but a true one about the whole hypothetical proposition. The same holds for a conjunctive proposition and the other hypotheticals. This is therefore a sign that the hypothetical, insofar as it is such, pertains to the character of enunciation, since it signifies a truth or falsity distinct from the categorical proposition, which is the essence of enunciation. Thus, just as complex and incomplex terms agree univocally, although one signifies a composite thing and the other a simple one, so hypothetical and categorical propositions agree univocally in signifying truth, although one is simple and the other composite.

I SAY, SECOND: Conjunctive and disjunctive propositions truly and in the strictest sense are hypothetical propositions.

This is stated expressly by St. Thomas, opusc. 48, treatise On Enunciation, chapter 14.⁶ “A hypothetical proposition,” he says, “is divided into three species: one is conditional, another disjunctive, and another conjunctive.” He says the same in the same work, treatise On Syllogism Simply So, chapter 16.⁷

And THE REASON FOR THIS is that they meet the definition of a hypothetical proposition, which St. Thomas defines as “that which has two categorical propositions as its principal parts.” This is most evident in a conjunctive or disjunctive proposition. Also, the truth and judgment given about a conjunctive or disjunctive proposition differ from the truth and judgment given about a categorical one; more is required to verify one than the other. To verify a disjunctive proposition, it suffices for one part to be verified; to verify a conjunctive proposition, both parts must be verified. The judgment and truth about each categorical proposition separately differ from the judgment and truth about both together, and about whether not only one but also the other is so. This is much clearer in a disjunctive proposition: when one part is false, the whole disjunctive proposition is true. Therefore the judgment and truth of the whole differ from those of the part.

THE OBJECTIONS ARE ANSWERED.

First it is argued: St. Thomas expressly affirms that the division of proposition into categorical and hypothetical is a division of an analogate into analogates, as is clear in opusc. 48, treatise On Enunciation, chapter 6,⁸ because categorical enunciation is one simply, whereas hypothetical enunciation is one by conjunction.

He says the same in On Interpretation 1, lecture 8,⁹ where he says: “An enunciation is one absolutely if it signifies one thing of one thing, or one in a qualified sense, namely, if it is one by conjunction.” Therefore we say, contrary to St. Thomas, that this division is univocal.

And it is confirmed because a hypothetical proposition is called one in a qualified sense, or one by conjunction, insofar as it signifies many things nevertheless united by a certain conjunction. Therefore, at least in the character of a sign, a hypothetical proposition is one in a qualified sense. Therefore it is so also in the character of a proposition, for a proposition is essentially a sign. If, then, it is not one simply in the character of a sign, but only in a qualified sense, neither will it be one simply in the character of a proposition, which is essentially a sign, but only one in a qualified sense.

IT IS ANSWERED that in that work St. Thomas did not say absolutely that this division is a division of an analogate into analogates, but that it is divided “as an analogate into its analogates”—that is, it has the mode of an analogical division, though not its substance. St. Thomas likewise teaches in On the Power of God, question 9, article 2, reply to objection 6,¹⁰ that the division of substance into first and second is not a division of genus into species, but rather of an analogate into analogates. Nevertheless, as we shall see in Logic, it is commonly held that this division is univocal; St. Thomas is interpreted as speaking of an analogical division with respect to its mode.

This univocity in substance and analogy in mode consists in this: two things are considered in a proposition. One is considered with respect to substance, that is, the signification of truth or falsity, or of a complex object insofar as it can be enunciated and judged; in this respect, as we said, categorical and hypothetical propositions agree univocally. The other concerns the identity and unity of discourse insofar as it signifies absolutely; this belongs to the side of the matter, namely, significant discourse, just as in the case of a term whether it is complex or incomplex. With respect to this there is a mode of analogy, insofar as a hypothetical proposition is constituted from categorical propositions and truth is found first in a categorical proposition and afterward in a hypothetical one. But not every priority and posteriority entails true analogy, as is clear in numbers: one number is prior to another and composes it, yet they are not analogical in the character of number. Rather, priority and posteriority in participating in a superior character make for analogy. This explanation is taken from St. Thomas himself, On Interpretation 1, lecture 8,¹¹ where he says: “It is evident that an enunciation which is one by conjunction is also many, and is many insofar as it signifies many things and not one.” And below:¹² “Some enunciation is one simply insofar as it signifies one thing; some is many simply insofar as it signifies many things, but is one in a qualified sense insofar as it is one by conjunction.” Therefore only on the side of the thing signified, and of the unity or identity of signification, is signification called one simply or in a qualified sense. But with respect to the truth asserted and enunciated, St. Thomas does not deny that a hypothetical truth is one simply.

To the confirmation it is answered, first, that even if the character of sign, which is superior, is analogical, it does not follow that the inferior character is not univocal. This is clear in being, in which human being and plant agree analogically, though not with respect to the character of living thing or substance. Second, it is said that the character of sign is not absolutely the genus of a logical artifact, but is so under the character of an artful sign. Thus the character of sign, taken almost materially and absolutely, can be multiplied in simple and complex enunciation; but under the character of an artful, complex, enunciable thing it can have unity simply, insofar as it signifies one truth, even if it is hypothetical. In this way complex and incomplex terms are made univocal in the character of term, just as houses with only one room and houses with twenty rooms are univocally houses.

Second it is argued: A hypothetical proposition is not a single concept of the mind or a simple quality, but a number of ordered concepts, whereas a categorical proposition is one simple concept, as the probable opinion holds. Therefore they do not agree univocally.

IT IS ANSWERED that the argument proves that, in the being of a quality or in entitative and physical being, hypothetical and categorical propositions stand as one and many, which are one in a qualified sense and by unity of order. Nevertheless, in an artful and logical manner, they agree univocally in the character of enunciating truth. Thus, in the character of an enunciable artifact, a hypothetical proposition is one simply and in its own right. A vessel made from one continuous quantity of gold, or assembled from several separate pieces, is univocally a vessel in the character of an artifact, although not with respect to the physical character of quantity or of one substance. And the character of term found in the first operation, and discourse or syllogism found in the third, agree univocally in the character of a logical artifact, though not in physical unity.

To the confirmation it is answered that although a hypothetical proposition is composed from what is formal in a categorical proposition, this very formal element composes materially, not formally. Something is said to compose formally when its formality and essence consist in the character of a composing part, as matter and form do in physical things; in this way it is not divided alongside the whole, but is included in it. But when something is itself a certain whole, though it can compose another thing by means of its formal element—which the other essentially requires for its composition—it is not said to be formally a composing part, although it composes by means of its formal element, because formally it is not a part. Thus it can be a species divided alongside what it composes, just as binary and ternary are species of number, although ternary is essentially constituted from binary.

Finally it is argued against the second conclusion that a conjunctive or disjunctive proposition is not one proposition but many, joined only by the simultaneity of their combined utterance, since they have no truth other than that of their categorical propositions taken together or disjunctively. But such conjunction or disjunction does not make a distinct proposition, only an aggregation of several; therefore they are not species of enunciation.

The antecedent is proved: beyond the aggregation of categorical truths, a conjunctive proposition has no other truth than signifying that both categorical propositions are true, or, if it is disjunctive, that one is true. But this proposition, “Both of those propositions are true,” is a certain third categorical truth. Therefore there will never be a hypothetical truth that, insofar as it is such, is a species distinct from the categorical; if it has a distinct truth, that truth is as it were reflexive and is explained through the categorical proposition “Both are true” or “One is true.”

IT IS ANSWERED: The major is denied. In proof of it, it is said that from the aggregation of categorical truths, made disjunctively or conjunctively, another truth results. Because it depends on categorical truths, it is called a hypothetical truth, since it has categorical propositions as its principal parts. And although the reflexive signification, considered in the act as signified, by which both are said to be true is explained through a categorical proposition, this does not remove the fact that the object signified by that reflexive proposition—which is the hypothetical proposition itself—is in itself a certain truth that is not categorical but hypothetical. For that reflexive categorical proposition is true only because what it signifies is true. But what is signified is that not only one proposition but also the other is true, which is a hypothetical truth and not a simple one. If that reflexive explanation through a categorical proposition sufficed to remove hypothetical truth, then the conditional itself would not be hypothetical, and a syllogism would not be discourse consisting of propositions, since we define a conditional reflexively through one categorical proposition by saying it is a conjunction of several propositions by means of the particle “if,” and that a syllogism is discourse that infers a conclusion from premises. It does not follow, however, that a syllogism is not composite discourse or that a conditional is not truly hypothetical.